I believe that it was a little buggy back then (regarding the handling of string(=denotation) delimeters spreading over multiple lines (and/or when those delimiters (") where escaped...): maybe there is a simple and obvious modification).
Back then I did not bother about it..
If somebody provides a modification I can easily test its correctness.

Btw. Opal is a functional programming language developed in the 90s I guess at the Technische Universität Berlin.